1. Field of the Invention
The present invention relates to a lens tilt adjusting mechanism for adjusting the tilt angle of a lens (a lens element or a lens group).
2. Description of the Related Art
Lens tilt adjustment for adjusting the tilt of the optical axis of a lens element or a lens group relative to the optical axis (reference axis) of a lens system is known as a lens system adjusting method. For instance, in a conventional lens tilt adjustment, a lens frame to which at least one lens element is fixed and a lens frame holder which holds the lens frame are provided with two axially-opposed radial surfaces, respectively, and the conventional lens tilt adjustment is performed by inserting a tilt adjusting spacer (tilt adjusting member/tilt adjusting piece) selected from among a plurality of tilt adjusting spacers having different thicknesses between the axially-opposed radial surfaces at a specified circumferential position therebetween. Upon completion of this lens tilt adjustment, the lens frame and the lens holder are fixed to each other by a fixing device such as set screw or adhesive.
However, the workability of the lens tilt adjustment using a tilt adjusting spacer is not very good because it is difficult to handle a small independent tilt adjusting spacer.
Specifically, in conventional lens tilt adjusting mechanisms using tilt adjusting spacer, the workability of installing (inserting) and removing the tilt adjusting spacer is not very good, the fixing operation for fixing the lens frame and the lens holder to each other is complicated, and the direction of tilting the lens for adjustment is limited.